A conventional dental camera for determining the color of teeth is known from EP-A1-376 647. In a conventional device of this type, a light source irradiates an object such as, for example, a tooth. The reflected light is captured or sensed by an optic capture device and is conducted to a reflected light receipt element. The reflected light receipt element is, in this conventional arrangement, configured as a spectrometer. With this arrangement, it is possible to specify or evaluate the color of an object.
This conventional arrangement relies upon a capture or sensing of light which is reflected at an angle from the surface of an object. This conventional arrangement is, for all practical purposes, operable only to sense scattered light so that the actual effective rate of light capture or sensing is substantially low.
A diagnostic device for use in the dental field, disclosed in DE-OS 33 45 465, permits a co-axial capture or sensing of the light reflected from a tooth. In this conventional arrangement, a light guide rod is provided which is overlaid by two light guide elements. The reflected light is guided to a photo resistor, which registers the brightness of the reflected light. By means of a filter, the capture or sensing of the reflected light can be adjusted to the respective spectrum which is desired to be observed. In this conventional arrangement, a determination or evaluation of the grade of reflection from the teeth is possible; however, it is, for substantially all practical purposes, not possible to effect a color comparison of a tooth in order to thereby specify a suitable replacement tooth.
In connection with evaluation of color, it is especially important that the lighting situation be reliably reproducible. The light source comprises a predetermined emission spectrum and the reflected light receipt element that is, for example, a CCD-cell-operates at a predetermined spectral sensitivity. In connection with avoiding a false color sensing, it has become known to undertake a so-called white color comparison. A unit comprising a light source and a reflected light receipt element can be calibrated by use of such a white color comparison. The calibration is, of course, relevant for the respective unit only under the same lighting circumstances. If, for example, a bulb is used as a light source and a bulb exchange of the existing bulb for another bulb is necessary, a renewed or refreshed white color comparison must be undertaken. Also, in connection with such white color comparisons, the conventional diagnosis devices reveal only partial color deviations.
U.S. Pat. No. 6,246,471 teaches a unit for measuring color. The unit has a display that displays data on color and optical properties or status or other information.
There is a need for a dental camera that facilitates the process of producing images of a portion of a patient's mouth, particularly for analyzing the color of teeth.